dc.description.abstract | A first principles phase diagram calculation, that included
van der Waals interactions, was performed for the
system (1-X)$\cdot$MoS$_{2}$-(X)$\cdot$MoTe$_{2}$.
Surprisingly, the predicted phase diagram has
at least two ordered solid-solution phases, at $X \approx 0.46$,
even though all calculated formation energies are positive, in a ground-state
analysis that examined all configurations with 16 or fewer anion sites.
The lower-temperature {\bf $I$}-phase is predicted to transform to a
higher-temperature {\bf $I^{\prime}$}-phase at $T \approx 500K$,
and {\bf $I^{\prime}$} disorders at $T \approx 730K$. Both these
transitions are predicted to be first-order, and there are broad miscibility
gaps on both sides of the ordered regions. Both the {\bf $I$}- and
{\bf $I^{\prime}$}-phases are predicted to be incommensurate: {\bf $I$}-phase
in three dimensions; and {\bf $I^{\prime}$}-phase in two dimensions. | en_US |